Motor driven by water-currents.



No. 649,084. Patented May 8, I900.

S. N. STEWART.

MOTOR DRIVEN BY WATER CUBRENTS.

(Application filed Dec. 9, 1898.)

( No Model.)

WITNESSES: Q INVENI'OR @[z/esfer J7? wa fi' 9- BY Q 3 WW xv ATTORNEYNITED STATES PATENT FFICE.

SYLVESTER N. STEWART, OF VIENNA, AUSTRIA-HUNGARY.

MOTOR DRIVEN BY WATER-CURRENTS.

SPECIFICATION forming part of Letters Patent No. 649,084, dated May 8,1900.

Application filed December 9, 1898. Serial No. 698,741. (No model.)

T0 at whom it may concern:

Be itknown that LSYLvEsTEn N. STEWART, a citizen of the UnitedStates ofAmerica, residing at 5 Canovagasse, in the city of Vienna, Empire ofAustria-Hungary, have invented certain new and useful Improvements inMotors Driven by Water-Currents; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make anduse the same.

This invention relates to motors driven by the current of rivers, andhas for its object to cheapen the construction of such motors and toincrease their efficiency.

The essential part of this motor consists of a kind of screw arranged ona shaft mounted in a frame. This frame is arranged at the side of asuitable boat or vessel and is adapted to be immersed into the water andto be raised therefrom. Such a frame is provided at each side of theboat or vessel; but for more thoroughly utilizing the power of thecurrent two or more such frames may be provided at each side of the boatorvessel. In this case provision is made that one or more of the motorsat each side of the boat may be thrown into operation at will. The powerobtained by the motors is transmitted by any suitable gearing, such aschain and chainwheel gearing, to a shaft mounted on the deck of the boator vessel, which is preferably coupled with the shaft of adynamo-machine. Thus the mechanical energy of the flowing water istransformed into electrical energy, which may be conducted to workshopsand factories erected on shore for being utilized there, or themechanical energy obtained by the motor may be utilized in any waydesired for instance, for driving machinery of any kind mounted on theboat or vessel itself.

In the accompanying drawings, Figure l is a side elevation of a boatprovided with the improved motor. Fig. 2 is a plan, and Fig. 3 an endview, thereof. Figs. 4 and 5 show an end elevation and plan,respectively, of the motor proper on a larger scale. Figs. 6 and 7 showdetails.

As is seen from the figures, the motor is constructed on the principleof a screw-propeller and consists of blades a, which for the sake ofsimplicity and cheapness may be secured to the square shaft b withoutthe aid of hubs or bosses, as shown.

The motor-tl1at is to say, the screw and its shaft bis journaled in aframe 0, pivoted on arms 6, arranged on the deck d of the boat. Asimilar frame 0' is also connected to the arms c, said frame beinglocated above and extending outside of the frame a, as best shown inFig. 3, said frame 0 normally resting on the frame 0 and carrying amotor similar to that carried by the frame 0. By means ofsuitablehoisting-gear-such as rope Z, passing over pulley m and onto thewinding-drum it, operated by the handle 0, mounted on the frameworkf-the frames 0 0 may be raised from the water or lowered into the same,each frame having an independent hoisting-gear. The frames 0 0' might bestrengthened at their corners by iron rods or anglerods.

The dotted lines at the right-hand side of Fig. 3 indicate the positionof the frames 0 and 0 when both are raised. When it is desired todiminish the power, but without stopping it, the frame 0 is raised outof the current, leaving the frame 0 still in operating position. Byraising the frame 0, however, both frames 0 and 0 will be raisedtogether.

For deriving a sufficient amount of power from the current the blades aare set at angles of approximately thirty degrees and are constructed ofwooden boards h, secured to an arm 1,, fixed to the shaft 1), Figs. 5,6, and 7. The arm i is let in the shaft b, and its edges and outer endare beveled off at angles.

On comparing only the working surfaces of the blade of the improvedscrew and those of the screws as heretofore constructed the theoreticalefficiency of the former will be found smaller than that of the latter;but considering the losses of power due to friction caused by the greatweight the work furnished by the improved screw is greater than thatfurnished by a screw of the usual construction ofthe same size.Besides,the latter screw, even if constructed as lightly as practicable,will not be set in motion by a slow current, whereas theherein-described motor will be actuated by the weakest current and is,moreover, much cheaper, its cost of construction being only aboutone-fifth part of that of an ordinary screw.

The usual screw constructed of iron is well adapted to propel boats,because in this case it works under heavy pressure; but it is by far tooheavy and too expensive and has too small a working surface 'to utilizethe low pressure of the flowing water of a river.

The blades a are mounted on the shaft b, as

is shown in Figs. 4 and 5-that is to say, their center lines are atright angles to the axis of the shaft-and the face of the blades exposedto the action of the current forms an angle of thirty degrees orthereabout with such axis. In order to diminish the resistance of thewater, the edges of the rectangular blades are beveled, as shown inFigs. 6 and 7. For reinforcing the blades the face of the same isconnected with the shaft by an iron rod 70, Figs. 4 and 5. In order toenable the blades to remove any ice, the edges or faces of the bladesshould be covered with iron plates. Instead of one screw two or more maybe arranged on each shaft 1).

Owing to the fact that the shaft-carrying frames are so arranged thatone extends outwardly and downwardly over the other on each side of thefloat, the said frames and their shafts .may extend the full length ofthe float, the shafts being side by side or in the same horizontal planewhen immersed, each shaft having motion imparted thereto by a volume ofwater different from that which aotua'tes the next shaft. Therefore eachshaft can be made of the utmost length and will also receive andtransmit the power from the current undisturbed by any influence on thecurrent by another shaft.

Having thus described my invention and a manner in which it can beconstructed, without setting forth all of the various modificationsthereof, I declare that what I claim is 1. Awater-current motorcomprising a suitable float, a plurality of frames hingedly connected tothe side of said float, a shaft carried by each of said frames andprovided with angularly-set blades, the said frames extending one overthe other whereby they are adapted to support the shafts immersed sideby side, and means for raising one of the frames and its shaftindependently of the other. 4

2. A water-current motor comprising a suitable float, a plurality offrames hingedly connected to each side of said float, a shaft carried byeach of said frames on each side of the float, each shaft being providedwith angularly-set blades, the said frames extending one over the otheron each side of the float, whereby they are adapted to support theshafts immersed side by side, and means for raising one of the framesand its shaft independently of the other on each side of the float.

In testimony whereof I alfix my signature in presence of two witnesses.

SYLVESTER N. STEWART. -Witnesses:

ALvEsTo S. HOGUE, AUGUST FUGGER.

